Uber moved a fleet of self-driving vehicles to Arizona on Friday after California insisted it comply with local rules — a move that highlights the regulatory discrepancies governing this new technology between states.

The California Department of Motor Vehicles revoked the registration of 16 Uber cars Wednesday because Uber refused to apply for a permit for testing autonomous vehicles. Uber’s response: shipping the cars to a state where no such permits are required.

It’s a tactic that could have consequences for California’s future as a hub for self-driving technology, some experts said.

Though California allows companies to test self-driving vehicles on its roads, it has established strict regulatory barriers. For example, a company must gain approval from specific municipalities through which it plans to drive, according to Karl Brauer, executive publisher of Autotrader and Kelley Blue Book.